Conventionally, TN (Twisted Nematic) type liquid crystal display devices have widely been used as liquid crystal display devices. Liquid crystal layers of the TN type liquid crystal display devices are arranged in such a manner that two alignment layers, upper and lower alignment layers, are made different in rubbing directions so that liquid crystal molecules are in a twisted state (twisted orientation) when no voltage is applied. Display quality of the TN mode liquid crystal display devices largely depends on visual angles.
In view of the foregoing circumstance, there has been proposed a vertically aligned (VA) mode system for the TN mode liquid crystal display devices. The VA mode system uses a liquid crystal material having negative dielectric anisotropy and a vertical alignment layer. In the VA mode, a black display is carried out in a state in which no voltage is applied. Birefringence due to liquid crystal layers of vertical alignment in a state in which no voltage is applied is mostly compensated with the use of a phase difference plate having a negative anisotropy refractive index or the like, whereby a suitable black display is obtainable in very wide visual angle directions. It is therefore possible to produce a display having high contrast in wide visual angle directions.
An exemplary device of the liquid crystal display devices of the vertically aligned (VA) system is disclosed in Patent Literature 1.
In this liquid crystal display device 100, a pixel electrode 101 has subpixel electrodes 101a, 101a, 101a, as shown in FIG. 16(a). An opposed electrode 102, which faces the pixel electrode 101, has rivet sections 103 that are in the shape of a protrusion and are provided at respective central parts of the subpixel electrodes 101a . . . , as shown in FIG. 16(b).
The foregoing makes it possible to tilt an electric field generated perpendicularly on an electrode surface between the subpixel electrodes 101a . . . and the opposed electrode 102. Thus, when voltage is applied, the liquid crystal molecules tilt axially symmetrically in the vertically aligned mode. Thus, visual angle dependency is equalized, compared with a case in which the liquid crystal molecules tilt only in a single direction. Therefore, a very fine visual angle characteristic is obtainable in all directions.    [Patent Literature 1] Japanese Unexamined Patent Publication No. 2005-215352 (published on Apr. 21, 2005)    [Patent Literature 2] Japanese Unexamined Patent Publication No. 2001-109009 (published on Apr. 20, 2001)